Zusammenfassung

The ability to make sense of the perceptual world by discriminating features and categorizing objects is a basic cognitive capacity. In combined psychophysical-electrophysiological experiments we investigated the representation of stimulus-related information in the anterior inferior temporal (IT) cortex of macaque monkeys, while they were performing a categorization task. We used parameterized line drawings of faces and fish as stimuli, and we varied the relevance of the different features for the task. In our neuronal sample most of the cells responded to both types of stimuli. A subset of neurons was more selective for stimuli with certain combinations of feature values. Finally, a third group of neurons encoded parametric information, mainly about the features of the stimuli that were relevant for the categorization task. It is reasonable to hypothesize that these neurons became finely tuned to the critical subset of the stimulus features during the categorization training, reflecting the monkeys’ perceptual increase of sensitivity for these dimensions. The neuronal responses were typically greatly influenced by stimulus manipulations such as scale changes and rotations in the frontal plane. This finding shows that following extensive training with a class of stimuli, some neurons in IT encode parametric information about relevant features. In current experiments we are simultaneously recording from the prefrontal and the IT cortices, in order to study the communication of the critical stimulus information between the two areas and their role in shaping the behavioral decision.